Apparatus for fabricating isolated phase bus

ABSTRACT

The apparatus includes a pair of rotatable headstocks which are spaced apart. A side beam extends along at least a portion of the distance between the headstocks with the side beam being substantially parallel to a line connecting the centers of rotation of the headstock. The headstocks are respectively of a configuration to securely receive an end of a first one of a plurality of cylindrical workpieces. Support means is provided for rotatably supporting the plurality of cylindrical workpieces in end-to-end manner with the longitudinal axes thereof being substantially coincident. Controllable welding means and controllable cutting means are coupled to the side beam and are capable of linear translation therealong. Controllable drive means is provided for: rotating the headstocks so that the cylindrical workpiece secured thereto is caused to rotate about its longitudinal axis; causing the welding means to translate along the side beam; and causing the cutting means to translate along the side beam. Control means is provided for controlling the drive means and for: activating the welding means into welding operation; activating the cutting means into cutting operation; and, for coordinating the control function to weld a plurality of the cylindrical workpieces together in end-to-end manner and to then cut a plurality of openings in the welded together workpieces with the welding locations and the openings being substantially precisely located in a predetermined reproducible manner.

BACKGROUND OF THE INVENTION

The present invention relates to an isolated phase bus system, and moreparticularly to apparatus for fabricating such an isolated phase bussystem.

Various isolated phase bus systems have been disclosed heretofore.Exemplary isolated phase bus systems are shown in U.S. Pat. No.2,972,005, entitled, "Isolated Phase Bus Duct Apparatus", issued toBrealey et al on Feb. 14, 1961, and assigned to the assignee of thepresent application. Another exemplary isolated phase bus system isshown in U.S. Pat. No. 3,654,378, entitled "Bus Duct Assembly", issuedto Rehder on Apr. 4, 1972, and assigned to Canadian General ElectricCompany, Ltd.

In one typical system, a cylindrical bus conductor is secured to aplurality of spaced-apart relatively fragile insulator assemblies andmounted within a mating hollow cylindrically shaped enclosure which ismaintained at ground potential. Each insulator assembly electricallyinsulates the cylindrical bus conductor from the surrounding enclosureand also provides support for the bus conductor. Typically, an end ofthe insulator assembly is secured, e.g., welded, to the enclosure at oneof a plurality of mounting openings in the enclosure. Generally, thecylindrical bus conductor is respectively provided with mounting andaccess openings along its length through which mounting hardware, e.g.,threaded bolts, can be inserted for securing the bus conductor to anunsecured opposing end of each one of the insulator assemblies. Inaddition to its mounting openings, the enclosure is also provided withaccess openings which are useful for servicing and installationpurposes. The enclosure access openings are generally disposed in aposition in-line with the bus conductor access openings. As will beappreciated more fully later, the enclosure mounting openings shouldalso be disposed in a position in-line with the bus conductor mountingopenings.

Although the isolated phase bus systems heretofore discussed aresatisfactory for many applications, they do suffer from certainproblems. One such problem is that from a manufacturing standpoint, itis very difficult to satisfactorily align the access and mountingopenings in the bus conductor structure with the respective access andmounting openings in the enclosure structure. More particularly, theaccess and mounting openings in the bus conductor and mating enclosure,and the typical bus conductor mounting system associated therewith,impose substantial constraints upon the assembly of the isolated phasebus system. That is, in the assembly of such a system, after one end ofeach of the insulator assemblies is secured, e.g., welded, to theenclosure, the appropriate bus conductor openings must be carefully, andproperly aligned with the opposing end of each one of the now-securedinsulator assemblies. Indeed, if not properly aligned, proper mountingwithin the enclosure, and securing of the bus conductor to the opposingend of each one of the already secured insulator assemblies, becomesvery difficult.

To further appreciate the importance of: (1) the proper alignment of themounting openings in the bus conductor with the mounting openings in themating enclosure; and, (2) the proper alignment of the access openingsin the bus conductor with the access openings in the mating enclosure,reference will be taken to FIG. 1.

FIG. 1 schematically depicts an isolated phase bus system, generallydesignated 10, in which a cylindrical bus conductor 12 is disposed in amating cylindrical enclosure 14 and supported by double insulatorassemblies, 16A, 16B, at spaced locations along the length of the busconductor. The cylindrical bus conductor 12 and the enclosure 14 are ofapproximately the same length with each of the members 12, 14respectively comprising a plurality of segments joined togetherend-to-end to achieve the desired length. At spaced points along thelength of the bus conductor 12, the insulator assemblies 16A, 16B areprovided. The insulator assemblies 16A, 16B are angularly spaced, e.g.,90° apart, around the longitudinal axis of bus conductor 12 and securedto the conductor as shown more fully in the sectional view of FIG. 2.(Note that a sectional view taken along line 2A--2A of FIG. 1 issubstantially identical to the sectional view of FIG. 2). As shown bydashed lines in FIGS. 2, 3, substantial angular and longitudinalalignment is required between: the bus conductor mounting openings 18Cand the enclosure mounting openings 18E; and, the bus conductor accessopening 20C and the enclosure access opening 20E. Inspection of FIGS. 2,3 reveals that any misalignment between openings 18C and 18E placessevere stresses on the fragile insulator assemblies 16A, 16B. Indeed,such misalignment may render it impossible to properly assemble theisolated phase bus system 10 of FIG. 1.

In view of the importance of the previously mentioned angular andlongitudinal alignment of mounting and access openings in the busconductor and enclosure, fabrication of such isolated phase bus systemsinvolves techniques which require precise control. For example, onetechnique involves: laying out all the necessary openings on a flatsheet of metal; cutting the appropriate openings; then, rounding out theflat sheet of metal into a cylindrical shape. This method is timeconsuming and carries a high likelihood of creating serious errors inthe transformation from a two dimensional workpiece to a threedimensional workpiece. Other techniques which have been consideredinclude tracing predetermined patterns on already existing cylindricalworkpieces. Such techniques are generally awkward and inefficient.

Accordingly, a general object of the present invention is to provideapparatus for efficiently fabricating an isolated phase bus system ofthe type which includes a cylindrical bus conductor member insulatinglysecured within a mating enclosure.

Another object of the present invention is to provide such apparatus inwhich alignment problems associated with bus conductor and enclosureopenings are substantially reduced.

Another object of the present invention is to provide such apparatuswhich includes automated control means.

SUMMARY

In carrying out one form of my invention, I provide an apparatus forprocessing a plurality of cylindrical workpieces employed in thefabrication of an insolated phase bus system of the type which includesa cylindrical bus conductor and a mating enclosure therefor. Theapparatus includes at least one rotatable headstock which is of aconfiguration to securely receive an end of a first one of a pluralityof cylindrical workpieces of a first diameter. Support means is providedfor rotatably supporting the plurality of cylindrical workpieces whenthe plurality of cylindrical workpieces are disposed in end-to-endmanner such that the longitudinal axes thereof are substantiallycoincident. A side beam is provided adjacent to the headstock andextending along a line parallel to the axis of rotation of the rotatableheadstock. Controllable workpiece welding means is coupled to the sidebeam. The welding means is capable of linear translation along thelength of the side beam. Controllable workpiece cutting means is coupledto the side beam and is capable of linear translation along the lengthof the side beam. Controllable first drive means is provided forrotating the headstock so that the cylindrical workpiece secured theretois caused to rotate about its longitudinal axis. Controllable seconddrive means is provided for causing the welding means to translate alongthe side beam. Controllable third drive means is provided for causingthe cutting means to translate along the side beam. Processing controlmeans is provided and includes: first control means for controlling thefirst drive means; second control means for controlling the second drivemeans and the activation of the welding means into welding operation;third control means for controlling the third drive means and theactivation of the cutting means into cutting operation; and fourthcontrol means for coordinating the first, second and third control meansto weld a plurality of the cylindrical workpieces together in end-to-endmanner and to then cut a plurality of openings in the welded-togetherworkpieces with the welding locations and the openings beingsubstantially precisely located in a predetermined reproducible manner.

BRIEF DESCRIPTION OF THE DRAWINGS

My invention will be more fully understood and its several objects andadvantages further appreciated by referring now to the followingdescription, taken in conjunction with the accompanying drawings,wherein:

FIG. 1 is a partially cut away perspective view of one form of isolatedphase bus system to which the apparatus of the present invention isapplicable.

FIG. 2 is a sectional view taken along line 2--2, or 2A--2A, of FIG. 1.

FIG. 3 is a partial bottom view taken along line 3--3 of FIG. 2.

FIG. 4 is a schematic representation of one form of apparatus of thepresent invention.

FIG. 5 is a simplified block diagram of a portion of one form of controlmeans for the apparatus of FIG. 4.

FIG. 6 is a schematic representation of one form of apparatus of thepresent invention similar to the apparatus of FIG. 4 in which one formof the welding step of the present invention is schematically depicted.

FIG. 7 is a schematic representation, taken as in FIG. 6, in which oneform of the cutting step of the present invention is schematicallydepicted.

FIG. 8 is a diagrammatic representation showing the manner in which thecutting step shown in FIG. 7 is accomplished.

FIG. 9 is a schematic representation, similar to FIG. 4, showing apreferred form of applicant's invention in which a bus conductor isfabricated on one portion of the apparatus and a mating enclosure isfabricated on another portion of the apparatus.

FIG. 10 is a highly schematic representation of the control and drivemeans of the apparatus shown in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 4, one form of applicant's apparatus invention isgenerally designated 30. The apparatus 30 includes a pair of rotatableheadstocks 32A, 32B, each headstock being of a configuration adapted tosecurely receive an end of a first one of a plurality of cylindricalworkpieces of a given diameter. Exemplary cylindrical workpieces 44 areshown in phantom and will be discussed later. The rotatable headstocks32A, 32B, are disposed such that their axes of rotation aresubstantially coincident. The rotatable headstocks 32A, 32B, areseparately driven by drive means 34A, 34B respectively. A side beam 36is disposed adjacent to the headstocks 32A, 32B, and extends along aline parallel to the axis of rotation of the rotatable headstocks.Coupled to the side beam 36 is a pair of welding means 38A, 38B whichtypically comprise GMAWU units (gas metal arc welding units). Thewelding means 38A, 38B, are respectively coupled to the side beam 36 insuch a manner as to be capable of translation along the length of theside beam 36. More particularly, the welding means 38A, 38B arerespectively fixed to motorized carriages, each of which isindependently controlled and includes indicia means, e.g., digital readout, for displaying linear position along the side beam 36. Preferably,each such motorized carriage moves along the side beam as a result ofits motor driven pinion (not shown) engaging a rack (not shown) which isprovided along the length of the side beam 36. For purposes of clarity,the welding means 38A, 38B have each been simply illustrated as a singlemotorized unit. The first welding means 38A, and the second weldingmeans 38B, each includes a welding electrode 39A, 39B, respectively.

Also coupled to the side beam 36 is a cutting means 40 which includes acutting tool in the form of a torch 41. The cutting means 40 typicallycomprises a plasma arc cutting torch and, preferably includes automaticcontrol. One suitable cutting means is commercially available fromThermal Dynamics Corp. of New Hampshire under the designation PMC-70.The cutting means 40 is coupled to the side beam 36 between the firstand second welding means 38A, 38B in a manner such that it too iscapable of translation along the length of the side beam 36. Typically,the cutting means 40 is coupled to the side beam 36 through anothermotorized carriage (not separately shown). The apparatus 30 alsopreferably includes support means 42 for supporting the cylindricalworkpiece(s) 44. The workpiece support means 42 may simply comprise oneor more idler roll assemblies.

Apparatus control means 50 is provided for coordinating at least some ofthe functions of the various elements of the apparatus 30. The apparatuscontrol means 50 includes a control unit 46 which provides an operatorwith the ability to select one or more of several functions useful inthe fabrication of an isolated phase bus system such as the exemplarysystem 10 shown in FIG. 1. The control unit 46 may also include displaymeans relating to such fabrication.

Referring now to FIG. 5, a portion 50' of one form of the apparatuscontrol means 50 of FIG. 4 is further depicted in simplified blockdiagram form. The portion 50' is intended to depict that portion of theapparatus control means 50 of FIG. 4 which is directed toward therotation of the workpieces. In a preferred embodiment, the operatorcontrol unit 46 is coupled to coordinating control means 52 whichcomprises a digital computer, e.g., the one commercially available underthe designation Motorola #6800 series. The coupling between the operatorcontrol unit 46 and the coordinating control means 52 includes an INPUTA for activating the control means 52 and an OUTPUT A for indicating thestatus of the fabrication.

The apparatus control means 50' includes two rotational control loops.One control loop is an Analog Velocity Control Loop and the othercontrol loop is a Digital Position Control Loop. In response to INPUT A,the coordinating control means 52 produces a digital OUTPUT B which isconverted to analog form by a digital-to-analog converter 54. The analogoutput of the digital-to-analog converter 54 is directed to poweramplifier 56, e.g., the one commercially available under the designationWestamp #652. The electrical output of power amplifier 56 is directed tomotor 58 whose mechanical output is related to the magnitude of thepower amplifier output. The mechanical output, i.e., mechanicalmovement, of motor 58 is directed to move at least one of the operatingelements of the apparatus 30 shown in FIG. 4. For example, in theportion 50' of FIG. 5, the motor 58 may be coupled to the rotatableheadstock 32A wherein the mechanical output of motor 58 causes therotation of the headstock 32A. Typically, the motor 58 is coupled to theheadstock(s) through gearing means so as to provide various rotationalspeeds.

Referring now to the Analog Velocity Control Loop, the output of themotor 58 is measured by tachometer 60 which includes a high resolutionshaft encoder, e.g., the one commercially available under the designatedRenco Encoder. The electrical output of the tachometer 60 is directedback to the power amplifier 56 as a feedback input thereto. Thetachometer 60 is set at a value such that its output signal provides afeedback input signal which provides the desired power amplifier output,and hence, the desired mechanical output of motor 58.

The Digital Position Control loop continues from the motor 58 to a highresolution shaft encoder 62, e.g., the one commercially available underthe designation Renco Encoder. The shaft encoder 62 functions to developelectrical pulses representative of a predetermined mechanical motiondeveloped by the shaft of motor 58. For example, such a shaft encoder 62may develop an electrical pulse at each revolution of the shaft of motor58. Accordingly, depending upon the gearing between the motor 58 and therotated headstock 32A or 32B, each such electrical pulse is a measure ofsome incremental rotational movement of the rotatable headstock 32A or32B. The electrical pulses from the high resolution shaft encoder 62 aredirected back to the control means 52 through INPUT (B). The controlmeans 52 preferably includes a "counter" function which accumulates, orcounts, the electrical pulses from the high resolution shaft encoder 62.In one form of the present invention, the control means 52 includes a"counter" function which separately counts the electrical pulses fromthe high resolution shaft encoder 62 with pulses indicative of clockwiserotation of the rotatable headstocks 32A or 32B, adding to the controlmeans counter and pulses indicative of counterclockwise rotation of therotatable headstocks 32A or 32B, subtracting from the control meanscounter. In such an application, if the control means 52 is providedwith a particular count to look for (the count being representative of adesired rotation of the rotatable headstock 32A, 32B), the control means52 will cause the motor 58 to be driven (at a predetermined analogvelocity set by the tachometer 60) until that particular count isreached. Note that the above rotational counting function of the controlmeans 52 represents the angular position of the rotatable headstockswith respect to a given start point and can be displayed on the controlunit 46, if desired.

In addition to the portion 50' of the control means 50 shown in FIG. 5,control means are also respectively provided for the linear movement andactivation of the welding and cutting means 38A, 38B, 40 along the sidebeam 36. More particularly, such linear control means (not completelyshown in FIG. 5) is typically identical to the rotational control means50' except that two linear control loops and another motor, such asmotor 58, are provided to provide horizontal movement of at least one ofthe operating elements of the apparatus 30 shown in FIG. 4. For example,in the case of welding, another motor is operable to cause the weldingmeans 38A to move horizontally along the side beam 36 from one point toanother point. Preferably, for linear movement along the side beam 36,the mechanical output of the motor is separately coupled to each of theoperating elements through a rack and pinion drive (not shown). That is,each operating element has its own motorized carriage with a pinion forcoacting with a rack which is provided on the side beam 36.

In the linear control means, the shaft encoder 62 develops electricalimpulses in which each pulse is a measure of an incremental movement ofan operating element(s) along the side beam 36. The electrical pulsesfrom this shaft encoder are also directed back to a common control means52 though another INPUT B. The control means 52 includes a separate"counter" function which accumulates, or counts, these electrical pulsesfrom the high resolution shaft encoder 62. In one form of the presentinvention, forward direction pulses (pulses indicative of left-to-rightmovement along the side beam 36) add to the control means counter, whilereverse direction pulses (pulses indicative of right-to-left movementalong the side beam 36) subtract from the control means counter. In suchan application, if the control means 52 is provided with a particularcount to look for (the count being representative of a desiredtranslation along the side beam 36), the control means 52 will cause thelinear motor 58 to be driven (at the predetermined analog velocity setby the tachometer 60) until that particular count is reached.

As a safety measure, the control means 52 is preferably provided withthe capability such that, should an improper condition occur, such as aloss of control over the motor 58, where the motor 58 representsrotational or linear motor means, the control means 52 will stop allmotion because the observed counts are much greater than should beobserved in a particular time interval. Such capability can be providedby tachometer 60.

Referring to FIG. 6, a preferred form of the present invention will nowbe described. The apparatus, generally designated, 30', employed in thispreferred form of applicant's method invention is similar to theapparatus 30 of FIG. 4 with some modification thereof. Whereverpossible, the reference designations of FIG. 4 have been maintained. Theapparatus 30' shown in FIG. 6 may be considered as representing only aportion of the apparatus 30 of FIG. 4, omitting: the second rotatableheadstock 32B and its associated drive means 34B; and, the secondwelding means 38B. In place of the second rotatable headstock 32B, amovable roatable tail stock 64 is provided.

In carrying out the method of the present invention with the apparatus30' of FIG. 6, a first plurality of cylindrical metal workpieces 44₁ . .. 44_(N) of a given first diameter are provided. For example, in thecase of fabricating an enclosure for an isolated phase bus system, atypical cylindrical metal workpiece may be of the order of 3/8" thickand about 40" in diameter, with a total desired enclosure length ofabout 45 feet. These cylindrical workpieces 44₁ to 44_(N) are disposedin the apparatus 30' and aligned such that the longitudinal axes of thecylindrical workpieces 44₁, 44_(N) are substantially coincident. Thesupport means 42 and movable rotatable tailstock 64 are employed toassist in ensuring such coincidence. The movable rotatable tailstock 64is urged against the exposed end of the last cylindrical workpiece44_(N) to ready the plurality of cylindrical workpieces for the weldingstep.

The welding step comprises moving the welding means 38A to a positionalong the side beam 36 such that the welding electrode 39A is alignedwith the workpiece edges to be welded together. To provide the necessaryoperating room, cutting means 40 is generally moved to the right beyondthe tailstock 64. In FIG. 6, the welding means 38 is shown at position"10" (position 0 being a starting point left-to-right) on the side beam36 such that its welding electrode 39A is directly in alignment with thefirst weld (W1) going from left-to-right. Note that each cylindricalworkpiece 44 is typically of a given module length, i.e., 10 feet, suchthat the necessary welding step is repeated every 10 feet along thelength of the side beam 36. For example, in the apparatus 30' shown inFIG. 6, such welds W2, W3, W4 are eventually provided at locations 20,30, 40, along the side beam 36.

Referring again to the first weld, W1, when the welding means 38A, andits welding electrode 39A are properly located at W1 (position "10"),the drive means 34A rotates the rotatable headstock 32A, and hence, theentire assembly of cylindrical workpieces 44₁ . . . 44_(N), for a periodof rotation of 360°. During this 360° rotation, the welding electrode39A is activated so as to provide a complete weld W1. After completionof weld W1, the welding means 38 is moved along the side beam 36 wherethe process is repeated to produce weld W2. At the conclusion of thewelding step, the result is a plurality of cylindrical workpieces 44_(l)to 44_(N) welded together in end-to-end manner. It is to be appreciatedthat the welding step can be practiced manually or automatically or acombination thereof. That is, an operator may simply locate the weldingmeans 38A at the proper locations, e.g., (position 10, 20, 30, 40) and,at such location(s), then activate the welding electrode 39A and rotatethe rotatable headstock 32A for 360°. Alternatively, the positioning andactivation of the welding step may be automatically directed by thecomputer control means 52. That is, the computer control means 52 may beprogrammed to move the welding means 38 through the desired locations(10, 20, 30, 40) and, at such locations, activate the welding electrode39A and rotate the rotatable headstock 32A for 360°.

The next step in the method of the present invention is the cutting ofmounting and access openings 18E, 20E in the enclosure 14. Theseopenings 18E, 20E were previously discussed in connection with FIGS.1-3.

Referring now to FIG. 7, in carrying out the cutting step, the weldingmeans 38A is preferably moved to an extreme end (e.g., near position 0)of the side beam 36 as its function has been accomplished (compare FIGS.6, 7). In the cutting step, the cutting means 40 and its cutting tool 41are moved along the length of the side beam 36 in a predeterminedreproducible coordination with the rotation of rotatable headstock 32A.As shown in FIG. 7, the cutting means 40 has been moved from an initialleft-hand position to a position "22" along the length of the side beam36. In its movement along the side beam 36 from position "0" to position"22", the cutting means 40 has been selectively activated inpredetermined reproducible coordination with the rotation of therotatable headstock 32A so as to produce a plurality of openings 18E,20E. More particularly, as shown in FIG. 7, the cutting means 40 is inthe process of making mounting opening 18E in cylindrical workpiece 44₃.It is important to note that each of the already provided openings 18E,20E is precisely located both angularly and longitudinally in apredetermined reproducible manner, as required for the proper assemblyof isolated phase bus systems. More particularly, the centers of theopenings 18E, 20E are respectively aligned along the axes A, B, C and D,E, F (see also FIGS. 1-3).

Referring now to FIG. 8, a further discussion of the manner in which thecutting steps shown in FIG. 7 is accomplished is diagrammaticallydepicted. FIG. 8A shows a portion of the enclosure 14 (welded togetherworkpieces 44₁ . . . 44_(N)) at the initiation of a particular cut. Forthe purposes of illustration, the particular cut will be taken to be acircular cut such as the mounting opening 18E of FIGS. 2, 3, 7. Also,for purposes of illustration, the cutting means 40 will be initiallytaken to be at a reference location along the side beam 36 indicated atthe top of FIG. 8 as zero (0).

From the reference point zero (0) of FIG. 8A, the cutting means 40 isactivated and linearly moved to the right to position 1 at a constantrate while the enclosure 14 is rotated (via rotatable headstock 32A) ina counterclockwise or forward manner at a constant rotational rate,designated R_(F). The linear rate and the rate of rotation R_(F) aredetermined by the setting on the tachometer 60 and the gearing between:the motor(s) 58 and the element(s) on the side beam 36, and the motor 58and the rotatable headstocks 32A or 32B. The interaction of the linearmotion of the cutting means 40 from zero to 1 position and the forwardrotation R_(F) of the enclosure 14 produces a cut shown in dashed linesin FIG. 8B. While rotation of the enclosure 14 continues in this forwarddirection R_(F) at the same rate, the cutting means 40 is brought backto zero position. The result thus far is the half circle cut shown indashed lines in FIG. 8C. The cutting means 40 is then moved leftward toposition 2 while the enclosure 14 is rotated in a reverse directionR_(R), i.e., clockwise. The reverse rotation R_(R) is at the same rateof speed as the forward rotation R_(F). This results in the cut shown inFIG. 8D. The cutting means 40 is moved back to zero position whilecontinuing to rotate the enclosure 14 in the reverse or clockwisedirection R_(R). This results in the desired circular cut 18E shown inFIG. 8E. Thus, for such a circular cut 18E, the left and right linearspeed of the cutting means 40 is substantially the same and the forwardand reverse rate of rotation of the enclosure 14 is maintainedsubstantially the same. An important feature of the cutting step isthat, during the cutting, the distance from the cutting tool 40 to thesurface of the workpiece 14 to be cut is maintained substantiallyuniform. This uniformity of distance ensures accurate and efficientcutting.

It is to be appreciated that, it is preferable to precede thediagrammatic depiction of FIG. 8A with an initial locating position atthe center of the opening to be cut, and then to move outward to theperiphery of the opening.

For the circular type cut shown in FIG. 8, the relation between thelinear and rotational speeds during the cutting operation will now bediscussed. Referring to the half-circle cut shown in FIGS. 8A, 8B, 8C,the cutting means 40 should move the linear distance defined by position0 to 1 to 0 in the same time period that the cutting means 40 moves therotational (circumferential) distance defined by position R₀ to R₁. Forexample, consider the situation in which the complete rotation of therotatable headstock includes 360 increments as seen by the rotationalshaft encoder 62. In such a situation, the rotational distance definedby position R₀ to R₁ may, for example, comprise 20 increments and thelinear distance defined by position 0 to 1 to 0 may, for example, alsocomprise 20 increments as seen by the linear shaft encoder 62. For thissituation, the 20 rotational units should be counted in the same timeperiod as the 20 linear units. That is, the linear speed should be 20linear units over a time period t and the rotational speed should be 20rotational units over the same time period t. For some applications, itmay be useful to vary the rotational speed between positions R₀ to R₁with the speed being greater at, and near, these positions as comparedto positions therebetween. Such variation may be provided to compensatefor the "falling off" of the cylindrical surface of 14 at positions R₀,R₁. Such variation may be provided by programming the computer 52 ofFIG. 5 with the appropriate information. For further discussion,reference may be taken to U.S. Pat. No. 2,974,415, issued Mar. 14, 1961to Werner, entitled "Tool Guiding Device For Guiding A Tool Along TheCurves Of Intersection of Two Intersecting Tubes" for a discussion ofcutting cylindrical tubes.

The welding and cutting of the bus conductor member 12 (see FIGS. 1-3)are accomplished in substantially the same manner as previouslydescribed in connection with the fabrication of the mating enclosure 14.

In a preferred form of applicant's method, the cutting and welding ofthe bus conductor 12 are accomplished on the (right-hand) portion of theapparatus 30 of FIG. 4 not utilized in the apparatus 30' of FIG. 6. Moreparticularly, the cylindrical workpieces 44₁ . . . 44_(N) for thecylindrical bus conductor 12 can be disposed between the secondrotatable headstock 32B of FIG. 4 and a second movable rotatabletailstock 64, as shown in FIG. 9. For example, referring to FIG. 9, theleft-hand portion of the apparatus 30 of FIG. 4 is employed for thefabrication of the enclosure 14 and the right hand portion of theapparatus 30 of FIG. 4 is employed for the fabrication of the busconductor 12. The previously unutilized (right-hand) portion of theapparatus 30 also includes the second welding means 38B and employs thecommon cutting means 40. In carrying out this form of applicant's methodto fabricate the bus conductor 12, the welding step and cutting step areperformed in substantially the same manner as previously described inconnection with the enclosure 14 but the starting point for suchoperations is at a relative zero point at the extreme right-hand side ofthe side beam 36. This would produce a bus conductor 12 having welds andmounting/access openings 18C and 20C which are precisely located, bothangularly and longitudinally, in a predetermined reproducible manner.

An advantage of the foregoing form of applicant's invention in which thebus conductor 12 is fabricated on one portion of an apparatus and themating enclosure 14 is fabricated on another portion of the sameapparatus is that, if desired, the bus conductor 12 and mating enclosure14 can be fabricated substantially at the same time, or, during someoverlapping time period. Another advantage of this form of applicant'sinvention, as will soon be apparent, is simplified assembly of theisolated phase bus system.

With the now-completed bus conductor 12 and mating enclosure 14, thenext step is to assemble the isolated phase but system 10, as shown inFIGS. 1-3. This is accomplished by aligning the enclosure mounting,access openings 18E, 20E with the respective bus conductor mounting,access openings 18C, 20C. The relatively fragile insulator assemblies16A, 16B are then joined at one end thereof to the enclosure 14 and atthe opposing end thereof to the bus conductor 12, as shown in FIGS. 1,2. Typically, the joining of the insulator assemblies 16A, 16B, to theenclosure 14 is accomplished through the use of a welding interface W ateach enclosure opening 18E. The respective joining of the insulatorassemblies 16A, 16B, to the bus conductor 12 is generally accomplishedthrough the use of a threaded boss B at each conductor opening 18C. Theangularly and longitudinally aligned enclosure access openings 20E andbus conductor access openings 20C provide access to the assembler forproperly securing and/or servicing the insulator assemblies 16A, 16B.

It is important to appreciate that, as the openings cut in the enclosure14 and bus conductor 12 are processed in substantially the same manner,these openings are precisely, and reproducibly, located so that angularand longitudinal alignment is provided, as desired. This longitudinaland angular alignment reduces the possibility of physical stresses beingplaced upon the relatively fragile insulator assemblies 16A, 16B, duringthe assembly of the isolated phase bus system 10. When the bus conductor12 and mating enclosure 14 are fabricated on different portions of thesame apparatus, as in FIG. 9, if desired, the assembly of the isolatedphase bus system 10 can be simply initiated by sliding the smallerdiameter bus conductor 12 into the larger diameter mating enclosure 14.

It is not necessary that the bus conductor 12 and mating enclosure 14 befabricated on different portions of the same apparatus, as in FIG. 9.For example, the bus conductor 12 and the mating enclosure 14 can besuccessively fabricated on the same portion of the apparatus or onseparate apparatus, i.e., separate fixtures. Indeed, for someapplications, the foregoing successive fabrication on the same portionof the apparatus may be desirable as it results in a degree ofreproducibility which may be greater than that resulting from using thedifferent portions of the same apparatus.

GENERAL CONSIDERATIONS

Although the present invention has been described in connection with anexemplary isolated phase bus system 10 including double insulatorassemblies (16A, 16B of FIGS. 1, 2), the method and apparatus aregenerally applicable to other isolated phase bus systems. For example,for an isolated phase bus system including single longitudinally spacedinsulator assemblies, the problem of alignment of bus conductor openingsand mating enclosure openings would still be present, although to alesser degree. That is, although angular and longitudinal alignment ofthe appropriate openings is required, a fewer number of such openingswould be involved as compared to the number of openings involved in thedouble insulator assembly situation depicted in FIGS. 1-3. Indeed, themethod and apparatus of the present invention are generally applicableto isolated phase bus systems in which it is necessary to provide acylindrical bus conductor and a mating cylindrical enclosure with eachmember having at least two openings spaced along the length thereof withthe two openings of each of the members having a predetermined angularrelation therebetween with respect to the longitudinal axis thereof. Forexample, in a simple application, such two spaced openings along thelength of the bus conductor would be at substantially the same angularposition with respect to the longitudinal axis thereof. Further, themethod and apparatus of the present invention are also applicable to thefabrication of either the bus conductor or the enclosure in the isolatedphase bus system.

Referring now to FIG. 10, a highly schematic representation of thecontrol and drive means of the apparatus 30 of FIG. 4, and 30' of FIGS.6, 7, is depicted. For purposes of simplification, FIG. 10 depicts themultifunction capabilities of the apparatus of the present inventionseparately. It is helpful to refer to FIG. 10 as, in some applications,the entire multifunctional capability of the apparatus 30, 30', of thepresent invention may not be required. For example, the apparatus may berequired simply to provide precisely and reproducibly located openingswithout providing the welding function.

In FIG. 10, the rotatable headstock 32A is shown coupled to First Drivemeans 100 which may comprise the drive means 34A of FIG. 4. The FirstDrive means 100 is controlled by First Control Means 102 which maycomprise a separately operable subunit of a computer. The first andsecond welding means 38A, 38B are individually driven by Second DriveMeans 104 and Second Control Means 106 which is similar to First ControlMeans 102. Suitable Operation of First and Second Control Means 102, 106results in the previously described welding step. Such suitableoperation may be accomplished through Fourth Control Means 108 which,preferably, but not necessarily, comprises a computer. The cutting means40 is driven by Third Drive Means 110 and controlled by Third ControlMeans 112. Suitable operation of First and Third Control Means 102, 112,results in the previously described cutting step. Such suitableoperation of First and Third Control Means 102, 112 may be accomplishedthrough the Fourth Control Means 108. The functions of control means102, 106, 112, 108 of FIG. 10 may be conveniently viewed as containedwithin computer control means 52 of FIG. 5. In a preferred form ofapplicant' s invention, at least the cutting step is accomplishedthrough the use of computer control of the First Drive Means 100 and theThird Drive Means 110. That is, in such a preferred form, Fourth ControlMeans 108 comprises a computer which includes First Control Means 102and Third Control Means 112. An advantage of employing such a computeris that the computer can be programmed to reproducibly and automaticallycontrol the cutting and/or welding steps.

Although the method and apparatus of the present invention have beengenerally discussed in connection with circular openings, the inventionis generally applicable to openings of any configuration, e.g., square,rectangular, triangular, irregular, etc.

While I have illustrated preferred embodiments of my invention by way ofillustration, many modifications will occur to those skilled in the artand I therefore wish to have it understood that I intend in the appendedclaims to cover all such modifications as fall within the true spiritand scope of my invention.

What is claimed as new and desired to be secured by Letters Patent ofthe United States is:
 1. Apparatus for use in processing a plurality ofcylindrical workpieces employed in the fabrication of an isolated phasebus system, the isolated phase bus system being of the type whichincludes a cylindrical bus conductor and a mating enclosure therefor,which comprises:(a) at least one rotatable headstock, said rotatableheadstock being of a configuration to securely receive an end of a firstone of a plurality of cylindrical workpieces of a first diameter; (b)support means for rotatably supporting said plurality of cylindricalworkpieces when said plurality of cylindrical workpieces are disposed inend-to-end manner such that the longitudinal axes thereof aresubstantially coincident; (c) a side beam adjacent to said headstock andextending along a line parallel to the axis of rotation of saidrotatable headstock; (d) controllable workpiece welding means coupled tosaid side beam, said welding means being capable of linear translationalong the length of said side beam; (e) controllable workpiece cuttingmeans comprising a cutting torch coupled to said side beam, said cuttingmeans being capable of linear translation along the length of said sidebeam independently of said welding means; (f) drive means, whichincludes:(i) controllable first drive means for rotating said headstockso that the cylindrical workpiece secured thereto is caused to rotateabout its longitudinal axis, (ii) controllable second drive means forcausing said welding means to translate along said side beam; (iii)controllable third drive means for causing said cutting means totranslate along said side beam independently of said welding means; and(g) processing control means, which includes:(i) first control means forcontrolling said first drive means; (ii) second control means forcontrolling said second drive means and the activation of said weldingmeans into welding operation; (iii) third control means for controllingsaid third drive means and the activation of said cutting means intocutting operation and operable to activate said cutting means while saidcutting means is being translated along said side beam; and (iv) fourthcontrol means for coordinating said first, second and third controlmeans (a) to weld a plurality of said cylindrical workpieces together inend-to-end manner and (b) to then cut a plurality of openings in saidwelded-together workpieces, said welding locations and said openingsbeing substantially precisely located in a predetermined reproduciblemanner.
 2. Apparatus in accordance with claim 1 in which said supportmeans of 1(b) includes a movable rotatable tailstock, said movablerotatable tailstock being of a configuration to securely receive an endof a final one of said cylindrical workpieces and to assist in providingsupport for said plurality of cylindrical workpieces.
 3. Apparatus inaccordance with claim 1 which includes a pair of said rotatableheadstocks, said headstocks being spaced apart with said side beamextending along at least a portion of the distance between saidheadstocks, said side beam being substantially parallel to a lineconnecting the centers of rotation of said pair of headstocks. 4.Apparatus in accordance with claim 3 in which said workpiece weldingmeans includes first and second welding means respectively disposed onopposite sides of said workpiece cutting means, each of said first andsecond welding means being capable of separate control by said secondcontrol means of (g), (ii) of claim
 1. 5. Apparatus in accordance withclaim 1 in which said fourth control means includes computer controlmeans for coordinating said first and third control means.
 6. Apparatusin accordance with claim 4 which includes indicia by which the positionof said welding means and said cutting means along said side beam isdisplayed said indicia providing position information which includes thelongitudinal position of said cutting means and said welding means inrelation to said cylindrical workpieces.
 7. Apparatus in accordance withclaim 6 in which said indicia provides position information whichincludes the angular position of said cutting means and said weldingmeans in relation to said cylindrical workpieces.
 8. Apparatus for usein processing a plurality of cylindrical workpieces employed in thefabrication of an isolated phase bus system, the isolated phase bussystem being of the type which includes a cylindrical bus conductor anda mating enclosure therefor, which comprises:(a) at least one rotatableheadstock, said rotatable headstock being of a configuration to securelyreceive an end of a first one of a plurality of cylindrical workpiecesof a first diameter; (b) support means for rotatably supporting saidplurality of cylindrical workpieces when said plurality of cylindricalworkpieces are disposed in end-to-end manner such that the longitudinalaxes thereof are substantially coincident; (c) a side beam adjacent tosaid headstock and extending along a line parallel to the axis ofrotation of said rotatable headstock; (d) controllable workpiece weldingmeans coupled to said side beam, said welding means being capable oflinear translation along the length of said side beam; (e) controllableworkpiece cutting means comprising a cutting torch coupled to said sidebeam, said cutting means being capable of linear translation along thelength of said side beam independently of said welding means; (f) drivemeans, which includes:(i) controllable first drive means for rotatingsaid headstock so that the cylindrical workpiece secured thereto iscaused to rotate about its longitudinal axis, (ii) controllable seconddrive means for causing said welding means to translate along said sidebeam, (iii) controllable third drive means for causing said cuttingmeans to translate along said side beam independently of said weldingmeans; and (g) processing control means, which includes:(first controlmeans for controlling said first drive means, (ii) second control meansfor controlling said second drive means and the activation of saidwelding means into welding operation, (iii) third control means forcontrolling said third drive means and the activation of said cuttingmeans into cutting operation and operable to activate said cutting meanswhile said cutting means is being translated along said side beam, and(iv) fourth control means for coordinating said first, second and thirdcontrol means (a) to weld a plurality of said cylindrical workpiecestogether in end-to-end manner and (b) to then cut a plurality ofopenings in said welded-together workpieces, said welding locations andsaid openings being substantially precisely located in a predeterminedreproducible manner so that a cylindrical bus conductor fabricated fromcylindrical workpieces of said first diameter by the apparatus issubstantially mateable with a cylindrical enclosure fabricated fromcylindrical workpieces of a larger diameter by the apparatus, saidmateability including said openings of said welded-together firstdiameter workpieces being substantially longitudinally and angularlyaligned with said openings of said welded-together larger diameterworkpieces.
 9. Apparatus in accordance with claim 8 in which saidsupport means of 8(b) includes a movable rotatable tailstock, saidmovable rotatable tailstock being of a configuration to securely receiveand end of a final one of said cylindrical workpieces and to assist inproviding support for said plurality of cylindrical workpieces. 10.Apparatus in accordance with claim 8 which includes a pair of saidrotatable headstocks, said headstocks being spaced apart with said sidebeam extending along at least a portion of the distance between saidheadstocks, said side beam being substantially parallel to a lineconnecting the centers of rotation of said pair of headstocks. 11.Apparatus in accordance with claim 10 in which said workpiece weldingmeans includes first and second welding means respectively disposed onopposite sides of said workpiece cutting means, each of said first andsecond welding means being capable of separate control by said secondcontrol means of (g), (ii) of claim
 8. 12. Apparatus in accordance withclaim 8 in which said fourth control means includes computer controlmeans for coordinating said first and third control means.
 13. Apparatusin accordance with claim 11 which includes indicia by which the positionof said welding means and said cutting means along said side beam isdisplayed, said indicia providing position information which includesthe longitudinal position of said cutting means and said welding meansin relation to said cylindrical workpieces.
 14. Apparatus in accordancewith claim 13 in which said indicia provides position information whichincludes the angular position of said cutting means in relation to saidcylindrical workpieces.